Topiramate and risks in pregnancy
Key points
- Taking topiramate in pregnancy increases the risk of babies having problems when they’re born
- Rules about how topiramate is prescribed were introduced in June 2024
- You should be on effective contraception if you are able to get pregnant and you take topiramate
- Speak to your GP, epilepsy specialist or epilepsy specialist nurse if you are pregnant or planning a baby
- The patient guide provides more information about topiramate
What is topiramate?
Topiramate is a medicine used to treat epilepsy and prevent migraines. Topamax is one brand name of topiramate. The NHS website has more information, including side effects of topiramate.
The Medicines and Healthcare products Regulatory Agency (MHRA) introduced rules for prescribing topiramate in June 2024. This was after they reviewed evidence of the risks of taking topiramate in pregnancy to an unborn baby.
The rules aim to make sure people understand the risks of taking topiramate in pregnancy.
The guidelines used by healthcare professionals when they are prescribing topiramate talk about ‘women’. They use this to mean your sex assigned at birth. This may not be the same as your gender. The rules for topiramate apply to people assigned female at birth, who are able to become pregnant.
You can speak to your GP, epilepsy specialist nurse or specialist if you have any questions or concerns. Epilepsy Action’s helpline is also here to help answer any other questions you may have.
You should get medical advice before making any changes to your epilepsy medicines. The risk of uncontrolled seizures might outweigh the risks from topiramate to you and a baby.
What are the risks of taking topiramate in pregnancy?
Most people with epilepsy have healthy babies. 9 out of 10 babies born to mothers taking epilepsy medicines won’t have birth defects. But research has shown that topiramate can cause problems for babies if taken during pregnancy. The research focuses on these areas:
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Birth defects
Taking topiramate during pregnancy increases the risk of physical problems for the baby. These are called birth defects. Sometimes they’re called congenital abnormalities or congenital malformations.
A study looked at the risk of birth defects in the children of women taking one type of epilepsy medicine. It showed that if 100 people took topiramate during their pregnancy, 4 to 9 of the babies will be born with physical birth defects. This compares with 1 to 3 out of 100 in the general population. It’s thought that the risk increases with higher doses of topiramate. You should be prescribed the lowest dose that still controls your seizures.
Some examples of these birth defects include:
- Babies with a cleft lip or palate. This is where there is a split in the upper lip or roof of the mouth. It happens if a baby’s face doesn’t fully join together in the womb
- Baby boys may have an issue with their penis called hypospadias. This is where the hole at the tip of the penis that they pass urine through isn’t in the right place. Surgery might be able to fix it
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Babies weighing less than expected at birth
Taking topiramate during pregnancy also increases the risk of the baby being born smaller or weighing less than expected. Babies born smaller are more likely to become ill or have problems with learning and thinking.
If 100 people take topiramate during pregnancy, 18 babies will be born smaller or weigh less than expected. The same study found that 5 out of 100 babies are born smaller than expected to people without epilepsy.
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Issues with learning and development
Children might also have an increased risk of problems with learning and development. This could be:
- Autism spectrum disorders
- Attention deficit hyperactivity disorder (ADHD)
- Learning disabilities
The evidence from research looking into this topic is unclear. Some studies disagree with each other. More research needs to be done to fully understand the risks.
Contact our helpline
We understand that you might be worried about the rules and risks of taking topiramate. Epilepsy Action are here to help answer any questions you might have.
You can call our helpline or chat to us online.
What are the rules for taking topiramate?
If it’s possible for you to become pregnant, you should only be prescribed topiramate if you’re on the Pregnancy Prevention Programme:
- You can only be prescribed topiramate if you are using effective contraception. This could be a copper IUD (intrauterine device) or hormonal IUS (intrauterine system). Or, use condoms and another method. This is to lower the risk of harm to an unborn baby. Topiramate can affect how well some types of contraception work. More information can be found on our contraception page
- You should use contraception even if you’re not currently sexually active
- Your epilepsy specialist will discuss the risks and benefits of taking topiramate. They may discuss switching medicines and will review your medicine at least once a year. At these appointments they will complete an annual risk awareness form with you. This is to check that you understand the risks and why you need to use contraception
- You may be asked to do a pregnancy test to check you’re not pregnant
- Your epilepsy specialist should give you a copy of the patient guide and patient card. These explain the risks and guidance for you
Your epilepsy specialist should invite you for a review if you haven’t seen them since the rules were introduced June 2024. This is only if you’re at an age where you could become pregnant. You will then have a review each year with your specialist.
You shouldn’t make any changes to your medicines until you’ve spoken a specialist.
What if I’m pregnant or planning a baby?
You should contact to your GP urgently if you’re pregnant and taking topiramate. They will refer you to your epilepsy specialist who can discuss your options with you. You shouldn’t make any changes to your epilepsy medicine until then.
You and your epilepsy specialist might decide to switch to another medicine. Or, you might stay on topiramate if other medicines don’t control your seizures.
Sometimes the risk of uncontrolled seizures might outweigh the risks from topiramate for you and your baby.
If you are planning to have a baby, it’s recommended to speak to your epilepsy specialist before you become pregnant. Your GP will be able to refer you. This is so you have plenty of time to make any changes to your medicines before you become pregnant. Keep taking contraception until you’ve discussed your options with an epilepsy specialist.
Epilepsy Action has information about questions you might have when planning a baby.
Always get medical advice before making any changes to your epilepsy medicine.
Stopping your medicines suddenly can be harmful for you and your baby. It may make you have more seizures or seizures that are more severe. Uncontrolled seizures can increase your risk of sudden unexplained death in epilepsy (SUDEP).
What if my child is taking topiramate?
An epilepsy specialist should explain the risks of taking topiramate to you and your child if they were assigned female at birth. They should do this even if they have not started their period yet. This is so you’re prepared for the future.
Your child should see a specialist when they first start their period. They will help to decide whether topiramate is still the right medicine to take. A specialist should review your child’s medicine each year. They will complete the annual risk awareness form with you.
Do the rules about taking topiramate apply to men?
These rules only apply to people assigned female at birth who are able to become pregnant.
More support
We understand that the new rules can be worrying and confusing. Epilepsy Action will continue to update our website with the latest information.
Find out more about topiramate and pregnancy from the government website and patient guide. Speak to your epilepsy specialist, GP or epilepsy specialist nurse if you have any questions.
You might be worried that taking topiramate in pregnancy has affected your child. You can speak to your GP and there are organisations to support you. These include:
Organisation for Anti-convulsant Syndrome (OACS)
OACS support all families touched by Fetal Anti-Convulsant Syndromes
Tel: 07904200364
Email: oacscharity.org@gmail.com
INFACT
INFACT helps anyone that has taken anti-seizure medications in pregnancy. They offer information, advice and support. They can help if you’re concerned it may have affected your baby during pregnancy.
UK Epilepsy and Pregnancy Register
The UK Epilepsy and Pregnancy Register was set up to find out more about epilepsy and pregnancy. This includes taking epilepsy medicines during pregnancy. If you have epilepsy and are pregnant, you can visit their website or call on 0800 389 1248.
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